如何将 XML 反序列化为 C# 中的对象？ [复制]

Posted 2023-02-22

【中文标题】如何将 XML 反序列化为 C# 中的对象？ [复制]

【英文标题】：How to deserialize XML into an object in C#? [duplicate]

【发布时间】：2020-08-01 08:51:26

【问题描述】：

我需要读取 XML 并将其反序列化为 C# 中的对象。我使用 ToXmlFile(Object obj, string filePath) 函数的序列化部分创建了文件，如下所述。我在文件 test.xml 中创建了以下 XML：

<NYSE_Daily_Prices>
    <stock_exchange>NYSE</stock_exchange>
    <stock_symbol>ADI</stock_symbol>
    <date>2000-01-03T00:00:00</date>
    <stock_price_open>93.5</stock_price_open>
    <stock_price_high>93.87</stock_price_high>
    <stock_price_low>88</stock_price_low>
    <stock_price_close>90.19</stock_price_close>
    <stock_volume>3655600</stock_volume>
    <stock_price_adj_close>39.97</stock_price_adj_close>
  </NYSE_Daily_Prices>
  <NYSE_Daily_Prices>
    <stock_exchange>NYSE</stock_exchange>
    <stock_symbol>ADI</stock_symbol>
    <date>2000-01-04T00:00:00</date>
    <stock_price_open>89.5</stock_price_open>
    <stock_price_high>91.5</stock_price_high>
    <stock_price_low>85.56</stock_price_low>
    <stock_price_close>85.62</stock_price_close>
    <stock_volume>2533200</stock_volume>
    <stock_price_adj_close>37.95</stock_price_adj_close>
  </NYSE_Daily_Prices>
  <NYSE_Daily_Prices>
    <stock_exchange>NYSE</stock_exchange>
    <stock_symbol>ADI</stock_symbol>
    <date>2000-01-05T00:00:00</date>
    <stock_price_open>85.62</stock_price_open>
    <stock_price_high>88.25</stock_price_high>
    <stock_price_low>83.19</stock_price_low>
    <stock_price_close>86.88</stock_price_close>
    <stock_volume>3228000</stock_volume>
    <stock_price_adj_close>38.51</stock_price_adj_close>
  </NYSE_Daily_Prices>

这是我的对象：

public partial class NYSE_Daily_Prices
    
        public string stock_exchange  get; set; 
        public string stock_symbol  get; set; 
        public System.DateTime date  get; set; 
        public double stock_price_open  get; set; 
        public double stock_price_high  get; set; 
        public double stock_price_low  get; set; 
        public double stock_price_close  get; set; 
        public int stock_volume  get; set; 
        public double stock_price_adj_close  get; set; 
    

这是序列化/反序列化的代码：

public static class XmlHelper

    public static bool NewLineOnAttributes  get; set; 
    /// <summary>
    /// Serializes an object to an XML string, using the specified namespaces.
    /// </summary>
    public static string ToXml(object obj, XmlSerializerNamespaces ns)
    
        Type T = obj.GetType();

        var xs = new XmlSerializer(T);
        var ws = new XmlWriterSettings  Indent = true, NewLineOnAttributes = NewLineOnAttributes, OmitXmlDeclaration = true ;

        var sb = new StringBuilder();
        using (XmlWriter writer = XmlWriter.Create(sb, ws))
        
            xs.Serialize(writer, obj, ns);
        
        return sb.ToString();
    

    /// <summary>
    /// Serializes an object to an XML string.
    /// </summary>
    public static string ToXml(object obj)
    
        var ns = new XmlSerializerNamespaces();
        ns.Add("", "");
        return ToXml(obj, ns);
    

    /// <summary>
    /// Deserializes an object from an XML string.
    /// </summary>
    public static T FromXml<T>(string xml)
    
        XmlSerializer xs = new XmlSerializer(typeof(T));
        using (StringReader sr = new StringReader(xml))
        
            return (T)xs.Deserialize(sr);
        
    

    /// <summary>
    /// Deserializes an object from an XML string, using the specified type name.
    /// </summary>
    public static object FromXml(string xml, string typeName)
    
        Type T = Type.GetType(typeName);
        XmlSerializer xs = new XmlSerializer(T);
        using (StringReader sr = new StringReader(xml))
        
            return xs.Deserialize(sr);
        
    

    /// <summary>
    /// Serializes an object to an XML file.
    /// </summary>
    public static void ToXmlFile(Object obj, string filePath)
    
        var xs = new XmlSerializer(obj.GetType());
        var ns = new XmlSerializerNamespaces();
        var ws = new XmlWriterSettings  Indent = true, NewLineOnAttributes = NewLineOnAttributes, OmitXmlDeclaration = true ;
        ns.Add("", "");

        using (XmlWriter writer = XmlWriter.Create(filePath, ws))
        
            xs.Serialize(writer, obj);
        
    

    /// <summary>
    /// Deserializes an object from an XML file.
    /// </summary>
    public static T FromXmlFile<T>(string filePath)
    
        StreamReader sr = new StreamReader(filePath);
        try
        
            var result = FromXml<T>(sr.ReadToEnd());
            return result;
        
        catch (Exception e)
        
            throw new Exception("There was an error attempting to read the file " + filePath + "\n\n" + e.InnerException.Message);
        
        finally
        
            sr.Close();
        
    

以及我用来请求反序列化的代码：

string filePath = $@"C:\Users\dmast\Documents\Upskilled\C#\C# Programming Project\MoneyBMineWpfApp\MoneyBMineWpfApp\OfflineFilesXML\listRecentSearches.SelectedItem.ToString()";
            NYSE_Daily_Prices result = XMLReadWrite.XmlHelper.FromXmlFile<NYSE_Daily_Prices>(filePath);

我不断收到捕获的异常：

catch (Exception e)
                
                    throw new Exception("There was an error attempting to read the file " + filePath + "\n\n" + e.InnerException.Message);
            

任何帮助将不胜感激:)

【问题讨论】：

当抛出一个新的异常（顺便说一下，它不应该是基本异常类）时，只需将实际异常作为内部异常。现在，内部异常说明了什么？

throw 的参数包括 e.InnerException.Message，但您没有显示该 throw 的输出，也没有编写代码来显示 e.Message。

【参考方案1】：

戴维。你的代码对我来说看起来不错。我在本地试过。

您确定您提供了正确的文件路径吗？

我更改了一点 xml，因为我认为它应该有一个根元素。现在 .xml 文件如下所示：

<root>
  <Prices>
    <NYSE_Daily_Prices>
      <stock_exchange>NYSE</stock_exchange>
      <stock_symbol>ADI</stock_symbol>
      <date>2000-01-03T00:00:00</date>
      <stock_price_open>93.5</stock_price_open>
      <stock_price_high>93.87</stock_price_high>
      <stock_price_low>88</stock_price_low>
      <stock_price_close>90.19</stock_price_close>
      <stock_volume>3655600</stock_volume>
      <stock_price_adj_close>39.97</stock_price_adj_close>
    </NYSE_Daily_Prices>
    <NYSE_Daily_Prices>
      <stock_exchange>NYSE</stock_exchange>
      <stock_symbol>ADI</stock_symbol>
      <date>2000-01-04T00:00:00</date>
      <stock_price_open>89.5</stock_price_open>
      <stock_price_high>91.5</stock_price_high>
      <stock_price_low>85.56</stock_price_low>
      <stock_price_close>85.62</stock_price_close>
      <stock_volume>2533200</stock_volume>
      <stock_price_adj_close>37.95</stock_price_adj_close>
    </NYSE_Daily_Prices>
    <NYSE_Daily_Prices>
      <stock_exchange>NYSE</stock_exchange>
      <stock_symbol>ADI</stock_symbol>
      <date>2000-01-05T00:00:00</date>
      <stock_price_open>85.62</stock_price_open>
      <stock_price_high>88.25</stock_price_high>
      <stock_price_low>83.19</stock_price_low>
      <stock_price_close>86.88</stock_price_close>
      <stock_volume>3228000</stock_volume>
      <stock_price_adj_close>38.51</stock_price_adj_close>
    </NYSE_Daily_Prices>
  </Prices>
</root>

我又创建了 1 个班级 Root:

    [XmlRoot("root")]
    public class Root
    
        [XmlArray("Prices")]
        [XmlArrayItem("NYSE_Daily_Prices")]
        public List<NYSE_Daily_Prices> Prices  get; set;  = new List<NYSE_Daily_Prices>();
    

在控制台应用程序中测试了这段代码，它工作正常：

    class Program
    
        static void Main(string[] args)
        
            var deserializedObject = XmlHelper.FromXmlFile<Root>(Environment.CurrentDirectory + @"\file.xml");
        
    

希望对你有帮助！

【讨论】：

谢谢 Anna，您将根元素添加到 xml 文件是对的。我没有为调试文件添加位置。在我这样做之后，我执行了代码并接受了路径，但是由于重复的根元素，xml 文件有一个内部异常。现在一切正常:)